Inside the Southeast Expressway’s yellow zipper truck

About a dozen people responsible for opening and closing the South Expressway’s 6-mile-long high-occupancy lane using a pair of outdated machines that have long outlived their expected life. Thousands of commuters use the lane to zip between Braintree and Dorchester every weekday and many thousands more could find themselves stuck in gridlock if something were to go wrong.

As cars and trucks barrel toward him at highway speeds, Rob Bodoin eased a hulking yellow machine toward a row of concrete barriers, slowly feeding them between two rows of small rubber wheels beneath him.

“Now it’s going through the machine and it’s going to come out his end right here,” Bodoin said, referring to his partner, Bob Polchlopek, who was sitting on the opposite end of the 55-foot-long “barrier transfer vehicle,” better known as the zipper truck.

Bodoin and Polchlopek are part of a crew of about a dozen responsible for opening and closing the Southeast Expressway’s 6-mile-long high-occupancy lane using a pair of machines that have long outlived their life expectancy. Thousands of commuters use the lane to zip between Quincy and Dorchester every weekday, and many thousands more could find themselves stuck in gridlock if something were to go wrong.

“All you have to do is sit out there in the morning and you can see the traffic backed up at a quarter to 6,” said Bodoin, who has been opening and closing the lane for 18 years. “As soon as the lane opens, it starts filling up with people.”

“If the traffic is 5, 10 mph, and you get in the lane and you’re doing 55, you’re saving yourself 20 minutes,” he said.

First opened in 1995, the HOV lane was designed to provide an extra lane for northbound traffic during the morning commute into Boston by taking a lane from the southbound side – then doing the reverse for the evening commute. In between, the zipper crew uses two special machines to reposition a chain of about 10,000 linked concrete barriers, each one weighing 1,250 pounds.

The machines, which were built by California-based Barrier Systems, cost about $600,000 each in the mid-1990s and were expected to last no more than a decade. Today, nearly 20 years later, they are the oldest machines of their kind still being used.

But the two trucks may be finally approaching retirement. Sara Lavoie, a spokeswoman for the state Department of Transportation, said the agency expects to seek bids for new trucks this spring or summer and would receive the trucks between 2 and 2½ years after that.

In the meantime, the members of the zipper crew take obvious pride in keeping the machines running well past their expiration date.

“We open and close every single day and, weather permitting, we open on time,” Bodoin said.

The crew’s day starts around 3:30 a.m., when the morning shift arrives at a garage in the median of the expressway in Dorchester to prepare for the hour-long process of moving barriers on time to open the HOV lane for northbound traffic at 6 a.m. They then spend the next several hours performing routine maintenance on the trucks in a garage just north of the Braintree split.

Page 2 of 2 - We’re like a pit crew,” Bodoin says.

The process repeats itself when the barriers are moved to allow southbound traffic from 3 to 7 p.m.

Each truck is operated by two people: One who sits in a cab at the front and makes sure that the barriers are fed into a row of rubber “bogie wheels” that grips and lifts the concrete blocks and moves them through the machine; and another who sits in the back and makes sure the barriers are placed back down neatly on the other side of the lane.

Both cabs are outfitted with floor-to-ceiling windows, but the operators also rely on cameras, black-and-white monitors and an autopilot system that follows a wire laid in the roadway. The trucks can operate on autopilot alone if necessary – at least until something unexpected comes along.

“It can lay it out great, but what if something goes wrong, you know what I mean?” Bodoin said. “Anything can happen.”

What often happens is the crew comes across debris in the road and has to get out of the truck and remove it. Sometimes it’s something relatively harmless dropped by a driver, like a pair of sunglasses or a cellphone, but often it’s something more dangerous: hubcaps, construction debris, tires, road kill and, once, a stranded-but-still-alive baby deer.

The crew is often moving the barriers when the lanes next to them are full of speeding cars and trucks, sometimes coming at them head on. The barrier itself remains between the truck and the traffic as it’s moved, but Bodoin and Polchlopek said the experience is still unsettling at first.

“I bumped mirrors once with a bus – the bus was doing 70 mph or whatever – but other than that, you get used to it,” Bodoin said.

Back at the Quincy garage, a break-room refrigerator is topped with a trophy of sorts: the head from the first mannequin that somebody tried to use to cheat the occupancy requirement for the Southeast Expressway HOV lane when it first opened.

Nearly 20 years later, the zipper crew is ready to retire the twin trucks, but not without some misgivings.

“Taking care of (them) all these years – yeah, I’ll miss it,” Bodoin said. “But what are you going to do?”